Contrasting chemical and isotopic compositions of organic matter in Changjiang (Yangtze River) estuarine and East China Sea shelf sediments
Contrasting chemical and isotopic compositions of organic matter in Changjiang (Yangtze River) estuarine and East China Sea shelf sediments
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长江口和东海陆架沉积物有机质化学和同位素组成对比
DOI：
10.1007/s10872-008-0025-1
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发表时间：
2008-04
影响因子：
2.3
通讯作者：
中科院分区：
文献类型：
--
作者：
为探讨东海陆架沉积物中有机质的来源和保存，对长江口附近和东海陆架的3个沉积物柱样进行了碳氮比、碳同位素、有机生物标志物（正构烷烃和脂肪酸）和化合物（脂肪酸）稳定碳同位素的测定。对比化学和同位素组成的有机质之间的河口和陆架沉积物观察。陆架表层沉积物（0- 2cm）中总正构烷烃和脂肪酸的浓度比河口表层沉积物高5-10倍，但在表层以下迅速下降到相当水平。河口沉积物正构烷烃组成以C26-C33长链烷烃为主，具有较强的奇偶碳数优势。陆架沉积物中正构烷烃的组成以nC 15 ~ C22化合物为主。长链（>C20）脂肪酸（陆地生物标志物）在河口沉积物中的含量显著高于陆架沉积物，而短链（<C20）饱和和不饱和脂肪酸在陆架表层沉积物中的含量高于河口沉积物。各脂肪酸的稳定碳同位素比值从河口沉积物到陆架沉积物总体上呈现正向变化，这与δ 13 CTOCTOC的变化一致。河口沉积物与陆架沉积物的对比表明，陆源有机质主要沉积在长江口和东海陆架内。沉积后的成岩作用迅速改变了表层沉积物的化学成分，控制着该地区有机质的保存。
To examine the source and preservation of organic matter in the shelf sediments of the East China Sea (ECS), we measured bulk C/N and isotopes, organic biomarkers (n-alkanes and fatty acids) and compound-specific (fatty acids) stable carbon isotope ratios in three sediment cores collected from two sites near the Changjiang Estuary and one in the ECS shelf. Contrasting chemical and isotopic compositions of organic matter were observed between the estuarine and shelf sediments. The concentrations of totaln-alkanes and fatty acids in the shelf surface sediments (0–2 cm) were 5–10 times higher than those in estuarine surface sediments but they all decreased rapidly to comparable levels below the surface layer. The compositions ofn-alkanes in the estuarine sediments were dominated by C26-C33long-chainn-alkanes with a strong odd-to-even carbon number predominance. In contrast, the composition ofn-alkanes in the shelf sediment was dominated bynC15tonC22compounds. Long-chain (>C20) fatty acids (terrestrial biomarkers) accounted for a significantly higher fraction in the estuarine sediments compared to that in the shelf sediment, while short-chain (<C20) saturated and unsaturated fatty acids were more abundant in the shelf surface sediments than in the estuarine sediments. Stable carbon isotopic ratios of individual fatty acids showed a general positive shift from estuarine to shelf sediments, consistent with the variations in bulkδ13CTOCTOC. These contrasts between the estuarine and shelf sediments indicate that terrestrial organic matter was mainly deposited within the Changjiang Estuary and inner shelf of ECS. Post-depositional diagenetic processes in the surface sediments rapidly altered the chemical compositions and control the preservation of organic matter in the region.
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影响因子：
4.5
作者：
Boschker, HTS;Kromkamp, JC;Middelburg, JJ
通讯作者：
Middelburg, JJ
DOI：
10.1017/s0025315400039606
发表时间：
1986-02
影响因子：
1.2
作者：
A. C. Neal;F. Prahl;G. Eglinton;S. O'Hara;E. Corner
通讯作者：
A. C. Neal;F. Prahl;G. Eglinton;S. O'Hara;E. Corner
DOI：
10.1016/s0967-0645(03)00010-9
发表时间：
2003-03
影响因子：
3
作者：
Hung-Jen Lee;S. Chao
通讯作者：
Hung-Jen Lee;S. Chao
影响因子：
2.8
作者：
Xuchen Wang;Robert F. Chen;A. Berry
通讯作者：
Xuchen Wang;Robert F. Chen;A. Berry
影响因子：
3
作者：
C. Reddy;T. Eglinton;R. Palić;Bryan C. Benitez-Nelson;G. Stojanović;Ivan R. Palić;S. Djordjevic;G. Eglinton
通讯作者：
C. Reddy;T. Eglinton;R. Palić;Bryan C. Benitez-Nelson;G. Stojanović;Ivan R. Palić;S. Djordjevic;G. Eglinton